Immunoglobulin Y (IgY), the major antibody class in birds, has gained increasing attention in recent years as a versatile and ethically sustainable alternative to mammalian immunoglobulins. IgY has demonstrated strong potential in diagnostics, prophylaxis, and therapy across a wide range of fields, including infectious diseases, allergy management, oral health, and food safety. Its applications in animal health—particularly in poultry, livestock, and companion animals—further underscore its relevance within the One Health framework. This review provides a comprehensive synthesis of IgY technology, starting with its physiological role in maternal immunity and the structural characteristics that distinguish it from mammalian immunoglobulin G (IgG). This review outlines current strategies for IgY production and purification. It also provides an overview of its biomedical and veterinary applications, including its use in diagnostics, prevention, and treatment—such as for SARS-CoV-2—primarily based on studies published in the past five years. The final section addresses the current limitations of IgY technology, such as variability in protocols, stability challenges, and the need for safety assessment, while highlighting the importance of harmonized guidelines to support broader implementation. With growing scientific interest, expanding clinical research, and increasing availability of commercial products, IgY is well positioned to become a valuable immunobiological tool for both human and veterinary applications.

Three hyperimmune egg-based formulations rich in immunoglobulin Y (IgY) were orally administered (daily, for up to 90 days) to C57BL/6 mice that were not microbially challenged. The serum levels of 32 cytokines were quantified every 30 days. Histopathology, hematology, and serum biochemistry investigations were also performed. As a sign of increased immune activity, lymphohistiocytic infiltrates were detected in the digestive tract and the liver after 30, 60, and 90 days of treatment. These infiltrates were also present in the lungs after 30 and 60 days, but not at 90 days. Blood analysis indicated systemic inflammation after 30 days of treatment: increases in pro-inflammatory cytokines, glycemia, total serum proteins, ALT, and ALP. After 60 and 90 days of treatment, the analyzed blood parameters showed mixed signs of both increased and decreased inflammation. The increased cytokines, which varied with formulation and time of exposure, indicated a combination of mostly Th17- and Th2-type immune responses. As the mice were healthy and housed in standardized sanitary conditions, and were not microbially challenged, the data were consistent with an interaction of IgY with the gut-associated lymphoid tissue as the main mechanism of action. This interaction generated a local immune response, which subsequently induced a systemic response.

Machine learning (ML) is revolutionizing veterinary diagnostics by enhancing accuracy and efficiency across diverse areas such as imaging, disease prediction, histopathology, and genomics. Through its ability to process and learn from complex data patterns, ML enables earlier and more precise diagnoses, supports decision-making, and optimizes therapeutic interventions. However, challenges such as limited datasets, lack of standardization, and species-specific variability restrict widespread adoption. This review details major applications of ML in veterinary diagnostics, supported by examples from recent literature, and explores critical challenges and promising future directions for integrating ML technologies in veterinary practice.

Candida auris is an emerging multidrug-resistant fungal pathogen with a high affinity for skin colonization and significant potential for nosocomial transmission. This study aimed to develop and evaluate chitosan-based hydrogels loaded with nystatin and propolis as a topical antifungal strategy for skin decolonization of C. auris. The formulations were selected based on our previous results and optimized for cutaneous application. The internal structure of the hydrogels was investigated by polarized light microscopy, confirming the amorphous nature of propolis and the partial dispersion of nystatin. The antifungal activity was assessed against ten fluconazole-resistant C. auris strains. The CS-NYS-PRO1 formulation demonstrated the highest antifungal performance in the agar test, also reducing viable cell counts to undetectable levels within 6 h. Time–kill assays and SEM imaging confirmed the rapid fungicidal effect and revealed severe membrane disruption and cytoplasmic leakage. Molecular docking analyses indicated the strong binding of nystatin to both sterol 14α-demethylase (CYP51) and dihydrofolate reductase (DHFR) from C. auris, suggesting complementary membrane and intracellular mechanisms of action. These findings support the use of such hydrogels as a local, non-invasive, and biocompatible strategy for managing C. auris colonization, with promising implications for clinical use in infection control and the prevention of skin-mediated transmission in healthcare settings.

The mammalian gut microbiome functions as a metabolically active immunological organ and has co-evolved with its host to maintain systemic homeostasis. This review integrates current evidence on the molecular mechanisms governing bidirectional microbiota–immune communication, emphasizing evolutionary conservation, receptor-mediated signaling, and translational implications. Microbial structural ligands and metabolites—including short-chain fatty acids, bile-acid derivatives, and tryptophan catabolites—engage host receptors such as G-protein-coupled receptors, FXR/TGR5, and the aryl hydrocarbon receptor (AhR), thereby regulating epithelial barrier integrity, regulatory T-cell differentiation, Th17 polarization, mucosal IgA production, and systemic immune tone. Riboflavin-derived metabolites presented via major histocompatibility complex class-I-related molecule (MR1) further shape mucosal-associated invariant T-cell development (MAIT), illustrating metabolite-driven immune system programming. Dysbiosis induced by antibiotics, dietary perturbation, or aging disrupts these molecular networks, promoting chronic inflammatory, metabolic, autoimmune, and neuroimmune disorders. Comparative analyses across mammalian systems underscore conserved pathways of host–microbe coadaptation and immune education. Therapeutically, microbiota-modulating strategies—including probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), postbiotics, and IgY-based passive immunotherapy—aim to restore immunometabolic signaling. Emerging in vitro and in silico platforms further provide mechanistic precision while supporting ethically aligned translational research. Collectively, these insights position microbiota-derived molecular signaling as a central determinant of adaptive immune architecture and a targetable axis in precision immunotherapy.

Chronic Kidney Disease (CKD) is among the most frequent and clinically relevant metabolic disorders in cats, affecting a substantial proportion of the adult and geriatric feline population. The prevalence of CKD increases with age, being estimated at 20–50% in cats over 10 years of age. The etiology of this disorder involves genetic predisposition, dietary factors, as well as exposure to toxins or concomitant diseases that may accelerate the progression of renal lesions. The present study synthesizes data from the scientific literature together with clinical-epidemiological analyses performed on a cohort of 120 cats over a four-year period. The results highlighted an overall prevalence of CKD in the studied cohort, with a significantly higher frequency in cats over nine years of age, particularly affecting purebred animals. A slightly higher prevalence was observed in males compared to females, while reproductive status indicated an increased risk of CKD in neutered patients. Living environment and nutritional status were also influential, with a higher disease prevalence in indoor-only cats and in those fed nutritionally deficient diets. The multifactorial nature of CKD pathogenesis, combined with the nonspecific clinical manifestations in its early stages, explains the frequent late diagnosis of most cases. Consequently, an in-depth understanding of the epidemiology and associated risk factors constitutes an essential prerequisite for the development of preventive strategies, early screening protocols, and personalized therapeutic management aimed at optimizing quality of life and longevity in feline patients.